That way, Frodo starts out near-death from exposure to the outside world, but ends up happy at home, blissfully ignorant of what's going on outside the shire, while his ancient and powerful Supreme Leader takes care of all that messy 'freedom' stuff....
If you will always be in the same location as all the systems you're outfitting, go with what you can provide adequate support for (Linux/Open Source, I presume).
If these systems are going to be scattered around the globe, go for Windows. Say what you will about Windows, but you'll find on-site support in damn near every country you travel to.
Macs might be a good option if they'll be deployed to major metropolitan cities only (NY, LA, London, etc.).
Slow news day, huh?
WotC attacks the gazebo!
HELP!!!! I'm being held prisoner in /usr/games/lib!